The Tinhorn occurrence is located on the north side of Tinhorn Creek, 5 kilometres southwest of Oliver, British Columbia. It lies along the southern edge of the historic Fairview mining camp.
The Tinhorn, Big Horn and Fortune claims were first staked on a quartz vein in quartzites of the Kobau Group in 1896. The claims were owned and operated by the Tinhorn Quartz Mining Co. Ltd. The Tinhorn workings were mostly completed by 1897. Development includes five adits driven into the veins on the former Tinhorn and Fortune Crown grants. The main adit was driven sixty metres west and included a 19.5-metre shaft and an 8.0-metre raise. Another adit, located approximately 120 metres northeast, was driven to the west 25 metres in length. To the north, three shorter adits are driven on similar east striking quartz veins. In 1942, K.G. Ewers and I.A. McKay acquired ownership and operated the Tinhorn mine. Lawrence Mining Corp. conducted a soil sampling program over the Tinhorn underground workings in 1984. Gold anomalies up to 3 parts per million were identified. The former Tinhorn mine was restaked as part of the Joe Dandy Group in 1987 by Shangri-La Minerals and work carried out under option to Yuriko Resources Corp. An extensive program of prospecting, surface and underground rock sampling, soil sampling, geological mapping and magmatic and electromagnetic surveys was conducted. Limited geological mapping was also conducted in 1989. The first K.Q. claims were staked in the fall of 2005 by E.K. Nelson and work performed in 2006 consisted of prospecting and 5 rock samples sent for analysis. In 2014 and 2019, Hi Ho Silver Resources Inc. completed minor programs of rock sampling and structural analysis on the area as the Fairview property.
The Tinhorn occurrence lies within the Okanagan Terrane of the Intermontane tectonic belt. Polydeformed and regionally metamorphosed rocks of the Carboniferous to Permian Kobau Group dominantly underlie the area. Highly deformed, low grade metamorphic quartzite, phyllite, schist, greenstone and marble comprise the main units of a 1900-metre structural succession. Three phases of fold have been identified in the Kobau Group rocks. The initial phase of folding was coincident with pre-Jurassic regional metamorphism, whereas later phases of folding are related to intrusive activity. The main intrusions in the Fairview camp are the Jurassic Oliver granite and the Jurassic to Cretaceous Fairview granodiorite. The Oliver pluton is heterogeneous and is composed of biotite-hornblende granite, porphyritic biotite granite, garnet-muscovite granite, porphyritic quartz monzonite and syenite. Other intrusive phases cutting the Kobau Group metasediments and volcanics include aplite dikes, granitic, dioritic and mafic stocks, auriferous quartz veins related to Jurassic intrusions and Tertiary northeast-trending mafic dikes.
The Tinhorn occurrence is hosted within quartzite (KQ1) of the Carboniferous to Permian Kobau Group (Fieldwork 1988, pages 19-25). The unit is composed of quartzite layers 1 to 5 centimetres thick separated by biotite-rich layers, some biotite-rich sections and lenses of mafic schist.
East striking, steeply south dipping, parallel quartz veins 10 centimetres to 1 metre wide host the mineralization. The veins conform to the schistosity of the wallrock and contain pyrite, galena, sphalerite, free gold and telluride. Malachite staining is also present. North striking, west dipping faults 5 to 10 metres apart are reported to displace the quartz veins to the right a few metres. However, underground workings failed to find the extension of the vein system beyond one fault. An outcrop 200 metres higher in elevation along strike may be the extension.
There is little evidence of attempts to locate the vein in the 200 metre gap between the upper and lower adits. Soil sampling in 1983 located several gold anomalies on surface on unexplored ground to the north of the upper adit. Twelve rock samples were taken. Sample 11 yielded 0.99 gram per tonne gold and sample 12 yielded 1.10 grams per tonne (Assessment Report 12189). Rock chip sample JDK 306 yielded 15.36 grams per tonne gold and 17.2 grams per tonne silver, in 1988 (Yuriko Resources Corp. (1988): Prospectus). The sample was taken across the entrance to the No. 5 adit, from a blue-grey quartz vein hosted in oxidized and sheared phyllite.
Preliminary lead isotope studies indicate the mineralization is associated with quartz veins is younger than or as young as the Oliver pluton (circa 155 Ma) (Fieldwork 1988, pages 19-25).
Recorded production from the former Tinhorn mine totals 274 tonnes from which 1400 grams of gold and 467 grams of silver were recovered. Most the gold was recovered in 1898 from 181 tonnes mined. The remaining ore was recovered in 1942, probably from the old stamp mill tailings.
